Does the number of columns returned affect the speed of a query?

Question

If I have two queries

SELECT Id, Forename, Surname
FROM Person
WHERE PersonName Like(‘%frank%’)

And

SELECT *
FROM Person
WH         


        

Answer 1

Yes it does. Basically:

• More data has to be transfered from your database server
• The database server has to fetch more data

You shouldn't use select *